Category Archives: DXpeditions

I have enjoyed three to four medium wave and shortwave DXpeditions per year since 1988, to sites on the Washington and Oregon coasts. I love the chance they give to experiment with antennas in a (hopefully!) noise-free location, and concentrate on catching stations that might not be heard from home.

All of my DX trips have been via car–until now! I’ve just returned from nine vacation days in Hawaii (Waikoloa Beach, on the Big Island), and I thought others might like to see the radio related items I chose to take along for air travel. I’m pleased to report that everything worked as planned, and I have five days of SDR IQ WAV files of the MW band for review, all recorded in the time frame surrounding local dawn.

My goal was not the smallest, most compact portable setup, but one with high performance and modest size. Fitting everything into a day pack was another requirement. A simple wire antenna and an even smaller Windows tablet or laptop than the one I’ve used (and a smaller SDR like the HF+ Discovery, for that matter) would make a much smaller package. However, the items I’ve assembled worked excellently for me during my enjoyable Hawaii vacation. The directional loop antenna provided nulls on medium wave of 30 dB during preliminary tests indoors, a less-than-ideal test situation.

You’ll note the absence of headphones in the list. This is because my intent from the start was to record all the DX (MW band) as SDR WAV files for DXing post-vacation. That said, I did have headphones in my travel luggage for later spot checks of a few frequencies. That’s how I found 576 kHz Yangon, Myanmar lurking at their 1700 sign-off with national anthem and English announcement. The remainder of the DX to be uncovered will have to wait until I’m back home near Seattle!

The LMR-600 is a very thick and stiff coax cable, whose diameter approaches that used in the standard aluminum tubing ALA1530 series from Wellbrook. It has the benefit of being self-supporting in a 2-turn configuration and will also coil up into an approx. 12-inch package for transport. It just barely fits within the day pack I’m using. As I understand it, magnetic loops with tubing or large coax as the active element, versus simple wire, are more efficient in operation. Whether or not this holds true in practice remains to be seen.

I fashioned a wooden disc 3/4″ thick to attach the ALA1530 head amplifier, as I didn’t want to bring along a tripod or other support stand. The Wellbrook antennas all work well near or at ground level, so I was able to get great reception with the antenna right on the beach. The diameter at two turns of the coax is only a few inches smaller diameter than Wellbrook’s aluminum tubing loops. Three strips of strategically placed Velcro straps help keep the turns together when deployed as well as during storage.

In theory a two-turn loop should give 5 dB less gain than a single turn version; however, my older ALA1530 module has 5 dB more gain than the newer “LN” type, according to Andrew Ikin of Wellbrook Communications. The net result is that my two-turn antenna should have equal gain to the larger one-turn variety. Future experimentation with this DIY coax loop antenna is in order!

The Wellbrook loop antenna, RSPdx receiver, and Windows 10 tablet on the beach in Waikoloa, Hawaii.

Another view of the DXing position. Being this close to the water with my radio gear was unnerving at first, but the wave action on a calm Hawaii beach is totally different from the Oregon/Washington beaches with waves that can move in and out by a hundred feet or more.

The Wellbrook “DIY FlexLoop” works fine at beach level, and is less conspicuous this way, too.

The ALA1530 module is bolted to the 11-inch wooden disc for support. I’ve modified the module’s sockets to securely hold SO239 female connectors.

The commercial Wellbrook FLX1530LN is a fine product, and worthy of your consideration as a compact and high performance travel antenna. Full details can be found at this link.

SDR WAV Files for Download

One of my goals from the start for my Hawaii trip was to bring back SDR “IQ” WAV files for sharing with others. These approx. 900 Mb files cover the entire medium wave band as heard from my beach location in Waikoloa.

The overall page is: https://archive.org/details/@4nradio Clicking on any of the entries will bring you to a details page. From there just right click on the “WAVE” link, and choose “Save as…” to download. For a few of the recordings I also posted the file that precedes the one that goes across the top-of-the-hour, because things seemed a bit more lively prior to 1700 (which was at local sunrise, give or take a couple of minutes).

The IQ WAV files are only playable with suitable SDR radio software: SDRuno is first choice (but you need a RSP receiver connected). The files are also is compatible with HDSDR and SDR-Console V3. It may also play on Studio 1 software.

I hope other DXers enjoy the chance to tune through the MW band, as heard from the Big Island of Hawaii.

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington. He’s a regular contributor to the SWLing Post.

Many thanks to SWLing Post contributor, Joachim von Geisau (DH4JG), for the following guest post:

Signal distribution at SWL camps: The new JK-1000 HF distributor

by Joachim von Geisau (DH4JG)

The Friends of Radio NRW – an independent group of shortwave listeners and radio amateurs in Germany – have been organizing 2-3 SWL camps per year for a number of years, where they meet as far away as possible from electrical noise in order to listen to shortwave together.

To distribute antenna signals, we have previously used an RFT AVV01 antenna distributor.

At an SWL camp there are high demands on signal distribution. Both very weak and strong signals should be distributed well, un-distorted, without noise and other interference. The signal levels are approximately between 0.2 ?V (S1) to over 5 mV (S9 + 40 dB), with a frequency range of at least from 150 kHz to 30 MHz, thus broadcast bands from LW to SW are covered, also all amateur radio bands from 160 m to 10 m.

Popular among listeners are RFT AVV01 RF distributors from the former GDR, at least 30 years old. However, the use of an AVV01 has several disadvantages: high power consumption, difficulties in getting spare parts, high upkeep with corroded contacts and the like. In addition, the transmission of the LW/MW range drops, which is a disadvantage especially for MW listeners. The NV-14 system from Rohde & Schwarz from the late 1960s has the same weaknesses.

Two years ago, the desire arose to develop a concept for the replacement of the RFT system.
The following aspects were important:

Frequency range at least 100 kHz – 30 MHz, as linear as possible

frequencies below or above desirable

Running on 12 V DC or integrated noise-free power supply

Remote power supply for active antennas

Robust structure

Versatility

Hobby friendly budget

The amateur radio market offers several products for RF signal distribution (e.g., ELAD, Bonito et al.), but no solution to distribute 6-8 antennas to 10-12 receivers. It was clear from the beginning that DIY development was inevitable.

The starting point of the considerations was to integrate remote power supply for active antennas, an amplifier stage and a distribution network.

Such a distributor is able to distribute an antenna signal to several receivers; several antennas require several such distributors, which led to the decision to implement the project in plug-in technology.

With OM Frank Wornast DD3ZE (www.dd3ze.de), known e.g. for his converters, filters and the like, a well-known RF developer could be won, who took over the implementation of the concept based on the detailed specifications. OM Wornast first produced a prototype without remote power supply, which already did an excellent job of RF signal distribution.

A “hardness test” at an SWL camp showed that this distribution module easily fulfilled our requirements: Frequency range 10 kHz – 50 MHz (also usable with a few dB loss above 50 MHz). Supplemented by a switchable remote power supply and a 90V gas discharger at the antenna socket, the final PCB layout was created, representing the core of the new HF distribution system of Radio Freunde NRW

The device is characterized by a very smooth frequency response and has a very low inherent noise. It offers the possibility of using levels of -120dBm with very good SNR
to process up to strong levels of up to + 14dBm. In addition, the reception on VLF is now possible, which did not work with the previous system.

The PCB is designed in a very practical way: series resistors for LEDs are integrated as well as fixing points for coaxial cables. The remote power supply can be switched separately, but can also be used permanently by means of a jumper.

With this concept, the distribution block can be used universally: use on an active or passive antenna with distribution to several receivers, by means of a step switch in front of it also for several antennas; if you leave the remote feed path unconnected, the block can also be used as a simple distributor, so it is almost universal for hobby purposes.

For use on SWL camps, we decided to install them in 19 “rack-mount technology. A standard rack can thus accommodate 4 distributors and a power supply, allowing distribution of 4 antennas to 12 outputs each. An example of the installation is shown in the following picture: Parallel to the input is another BNC socket, which is connected via a C 100 nF where the input signal can be used DC-free for measurement purposes or the like. The distribution unit is installed in a transport case. The components themselves are mounted in slide-in housings which are provided with a corresponding front panel: Such front panels might be obtained from CNC manufacturers.

On the back + 12V DC must be supplied as operating voltage. For the power supply units, we opted for linear power supplies because we have made the best experience with these without interference. For a distribution unit with 4 slots, a power supply with 12V 1A is sufficient – each distribution block takes about 55 mA, an active antenna up to 150 mA, so even with “full load” a power supply with 1 A is sufficient. The distributor was tested with various well-known active and passive antennas, including a PA0RDT MiniWhip, active loops, long wires and T2FD.

Due to the wide input voltage range, the module can handle nearly any antenna. The cost for a distributor for 4 antennas amounts (depending on the version: housing, sockets, switches, power supply, etc.) to about 700-1000 €. That may seem a lot at first glance. However, taking into account that a simple 5-gang distributor from mass production costs already around 250 ¬, the cost of the distribution of 4 antennas to each up to 12 outputs are not that much. The Friends of Radio NRW use two of these distribution units for SWL camps.

If you are interested in building one, please contact the author (dh4jg@darc.de) for further information. The development history of the distribution unit is also available at www.dx-unlimited.eu.

Wow! What a beautifully engineered antenna distribution solution, Joachim! I love how you worked together to sort out all of the requirements for your system then build it for ultimate performance and flexibility. No doubt, you and your colleagues at Radiofreunde NRW posses a lot of design and engineering skills! Simply amazing and thank you for sharing your design with the radio community!

Many thanks to SWLing Post contributor Martin Butera, founding member of the 15.61 Crew, for the following guest post:

The 15.61 Crew Radio Listeners, Martin Butera and Ivan Dias, give us a small video preview made in the first Dx-Camp on Marajó Island in the Amazon Rainforest, North of Brazil on November 2019.

There are more than 11 hours of SDR recordings and videos of the Ultralight radios, which will take much additional time to process, of course.

Crew is working on the report with a complete story that includes videos and photos of everything experienced during the DX-Camp–this will be published in several languages and the first LOG, which we estimate will be the first months of the South American summer 2020.

Fulfilling our commitment to get involved in causes of direct action, instead of only DX we decided to do something.

For this reason we planted in the Marajó island a small tree in the name of the European DX Council (EDXC) which we affectionately baptized with the name “Chrissy”, referring to our friend Chrissy Brand, Chief Editor of BDXC bulletin and European DX Council (EDXC) Secretary, who supported this DXcamp.

We are aware that planting a tree in the midst of the flames that are killing the Amazon rainforest will not be its salvation, but will leave a legacy and is a way to contribute to a better world.

Help the environment does not require big actions, but small ones, such as:

Separate out our waste for later recycling;

Turn off the lights. It seems obvious, but we don’t realize how many times we turn on the light of a room we will not stay in;

Eat organic fruits and vegetables. Organic products help the environment because in their production no fertilizers or other polluting products are needed;

Turn off the faucet correctly. When you do not need water, turn off the faucet and check for leaks;

Go by bicycle or public transport. Pollution in big cities comes largely from the excessive use of cars;

Take your own bags to the supermarket. More and more supermarkets are selling plastic bags to avoid their use and encourage recycling;

Take advantage of natural light. To reduce the electricity consumption, open the windows and curtains so that sunlight enters your home;

Recycle everything you can. Before throwing clothes, books or toys, think about whether you can give them a second chance to avoid spending and buying everything new. You will save money and protect the environment.

As you could read, they are small actions that help energy saving, recycling and conservation of these resources.

After recently checking out a number of photos on the Radiofreunde NRW Facebook page, I asked if a member of this group could give me a little more detail about their DXpeditions. Many thanks to Joachim Geisau who writes:

Radiofreunde NRW is an independent association of SWL, radio amateurs and technology enthusiasts. We meet 2-3 times a year for a few days in a rural area far away from urban noise to listen to radio broadcasts from the most distant countries.

Normally we set up several large antennas, mostly 8-10 different ones, both active and passive.

Post readers: If you’re interested in Radiofreunde NRW’s events, you can contact them via their email address: info@radiofreunde-nrw.de They’re a multi-lingual group and can accommodate German, English, French, and Dutch!

“When the Last Tree Is Cut Down, the Last Fish Eaten, and the Last Stream Poisoned, You Will Realize That You Cannot Eat Money ” (Native American saying).

Vital to the planet weather, the Amazon region has suffered fires for several weeks and several organizations have denounced the silence of Brazilian President Jair Bolsonaro about what they consider a devastating environmental crime against Earth. Such disaster has caused worldwide shock and must be remembered, because as something that happened during September, unfortunately the media coverage is focusing probably another disaster.

Marajó is the largest island in Brazil and the largest river island in the world, where the Amazon and Tocantins rivers and the Atlantic Ocean meet. It’s located about three hours by boat from Belém, capital of Pará state.

The 15.61 Crew founders are Martín Butera, correspondent journalist in South America for the British DX Club and Ivan Dias da Silva Júnior, founder of the Regional DX group of Sorocaba/São Paulo.

The objective of 15.61 Crew is not just DX. We will take a direct and committed action to help the planet and raise awareness about the climate change that we are sadly living.

We will plant a tree on behalf of the European DX Council (EDXC). Planting a tree amid the flames that are killing the Amazon rainforest today will certainly not be your salvation, but it will leave a legacy and our contribution for a better world.

We will raise awareness that together we can change this situation with actions such like waste sorting, buying products that can be reused, lowering electricity consumption, eating more organic fruits and vegetables, moving on public transport and so on.

Martin Butera lives in Brasilia, the capital of Brazil, about 27 hours from Belém or 1982 km. Ivan, lives in Sorocaba,São Paulo state, 38 hours from Belém or 2893 km. Both will meet in Belém and then go by boat to the island.

A trip like this requires a lot of preparation. It’s not something cheap or easy to be done. It takes a lot of time, effort and personal expenses to go to these remote places in South America and then share our catches with you. Those who would like to collaborate with us can do by Paypal account, from our website.

Why do we ask your financial support? Airline weight limits and luggage size are a problem in South America and are increasing the costs for us. We also have a long boat trip of more than 3 hours and will rent a house in the island.

Everything is already paid, but your help can made everything easier on the next DXcamps of 15.61 Crew. All donations will be reported on our site, but whoever makes an anonymous donation will be kept anonymous, and we will report only the value. Please consider support our DXcamp camp in Marajó island!

Your contribution will help us take the best listening station we can gather and have more and better chances of getting good results.

The 15.61 Crew founders, have extensive experience in the hobby, both Martin, 29 years as a ham radio operator (LU9EFO-PT2ZDX), with many DXpeditions in several South American islands, as Ivan, started DXing 26 years ago, including contributions to several clubs and as utility stations professional monitor.

Everything we do during this DXcamp will be shared by texts, photos and videos of our correspondent Martín Butera and will be published as son as possible on the BDXC bulletin and SWLing Post blog.

This will be the first of many DXcamps in exotic places that we plan to carry out, always with a message and a proposal for direct action. We are living in a world in danger and our roles as a society can’t be limited only to be only radio listeners.

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